In the construction of steel frames for large trailers of all types, it is well known that it is highly advantageous to apply a camber to the main steel beams of the trailers, whether they are tubes, I-beams or C-channel. When trailer frames with appropriate cambers in their main beams are under load, the main steel beams bend until they are substantially straight, but do not sag, as would have been the case if the main steel beams lacked a camber before being put under load. Heretofore, cambers have been imparted to the main steel beams of trailers by applying heat to the top or bottom of the steel beams as a sharp bending force is applied to the opposite sides of the beams. The result has been cambers in the steel beam with relatively sharp kinks where bending forces have been applied during the heated cambering process.
The present invention provides a novel cold cambering apparatus and method for imparting cambers to the steel beams used in the manufacture of frames for trailers that eliminates the sharp kinks imparted to steel beams during the heated cambering process of the prior art. The present invention may be used to impart a cold camber to steel I- and C-channel beams, as well as tubes, either individually, or after they have been incorporated into a trailer frame. It has also been discovered that cold cambering imparts a camber that holds better than a comparable heat induced camber. In addition, the cold camber imparted to steel beams is in the form of a preferred long sweeping arch as opposed to the cambers with sharp kinks typically found in heat-induced cambers of the prior art.
One preferred embodiment of the present invention is a cold steel cambering apparatus, comprising, a moveable forward cambering assembly having a forward-most end and a rearward-most end and therebetween a plurality of adjustable beam guides, each having first means to restrain lateral movement of at least one cold steel beam placed on the forward cambering assembly, with a plurality of guides at the ends also having second means to restrain upward movement of at least one cold steel beam placed on the forward cambering assembly; and at least one forward hydraulic lift cylinder positioned midway between the ends and directly under at least one cold steel beam placed on the forward cambering assembly with third means to impart a concave camber to at least one cold steel beam placed on the forward cambering assembly over the forward hydraulic cylinder that is restrained by said first and second means; a moveable rear cambering assembly-aligned with the forward cambering assembly and.having a forward-most end and a rearward-most end and therebetween a plurality of adjustable beam guides,.each having fourth means to restrain lateral movement and fifth means to restrain upward movement of at least ore cold steel beam placed simultaneously on the rear cambering assembly and the forward cambering assembly, and at least one pair of rear hydraulic lift cylinders positioned to be at the rearward-most end portion of the rear cambering assembly and directly under at least one cold steel beam placed on the rear cambering assembly with sixth means to impart an upward camber to at least one cold steel beam placed on the rear cambering assembly over the rear hydraulic lift cylinders and restrained by the fourth and fifth means.
Another preferred embodiment of the present invention is a cold steel cambering apparatus, comprising, a cambering assembly having a forward-most end and a rearward-most end and therebetween a plurality of adjustable beam guides, each having first means to restrain lateral movement of at least one cold steel beam placed on the cambering assembly, with a plurality of guides at the ends also having second means to restrain upward movement of at least one cold steel beam placed on the cambering assembly; and at least one hydraulic lift cylinder positioned midway between the ends and directly under at least one cold steel beam placed on the cambering assembly with means to impart a concave camber to at least one cold steel beam placed on the cambering assembly over the forward hydraulic cylinder and restrained by the first and second means.
Another preferred embodiment of the present invention is a cold steel cambering apparatus, comprising, a cambering assembly having a forward-most end and a rearward-most end and therebetween a plurality of adjustable beam guides, each having first means to restrain lateral movement and second means to restrain upward movement of at least one cold steel beam placed on the cambering assembly, and at least one pair of rear hydraulic lift cylinders positioned to be at the rearward-mo st end portion of the rear cambering assembly and directly under at least one cold steel beam placed on the rear cambering assembly with means to impart an upward camber to at least one cold steel beam placed on the cambering assembly over the rear hydraulic lift cylinders and restrained by the first and second means.
Another preferred embodiment of the present invention is a method of providing a camber to a cold steel beam, comprising, providing a moveable forward cambering assembly having a forward-most end and a rearward-most end and therebetween a plurality of adjustable beam guides, each having first means to restrain lateral movement of at least one cold steel beam placed on the fo rw ard cambering assembly, with a plurality of guides at the ends also having second means to restrain upward movement of at least one cold steel beam placed on the forward cambering assembly; and at least one forward hydraulic lift cylinder positioned midway between the ends and directly under at least one cold steel beam placed on the forward cambering assembly with third means to impart a concave camber to at least one cold steel beam placed on the forward cambering assembly over the forward hydraulic cylinder and restrained by said first and second means; and a moveable rear cambering assembly aligned with the forward cambering assembly and having a forward-most end and a rearward-most end and therebetween a plurality of adjustable beam guides, each having fourth means to restrain lateral movement and fifth means to restrain upward movement of at least one cold steel beam placed simultaneously on the rear cambering assembly and the forward cambering assembly, and at least one pair of rear hydraulic lift cylinders positioned to be at the rearward-most end portion of the rear cambering assembly and directly under at least one cold steel beam placed on the rear cambering assembly with sixth means to impart an upward camber to at least one cold steel beam placed on the rear cambering assembly over the rear hydraulic lift cylinders and restrained by said fourth and fifth means; and at least one cold steel beam to be cambered; adjusting the separation between the rear and forward cambering assemblies in direct relation to the length of at least one cold steel beam of the providing step; first positioning of at least one cold steel beam of the providing step on the forward cambering assembly with the desired center of a forward concave camber to be imparted to at least one cold steel beam of the providing step over at least one of the forward hydraulic lift cylinder; second positioning of at least one cold steel beam of the providing step on the rear cambering assembly with the end of each beam overlaying at least one rear hydraulic lift cylinders; capturing at least one cold steel beam of the providing step with the forward and rear adjustable beam guides; first lifting at least one of the forward hydraulic lift cylinders to bend at least one cold steel beam of the providing step to a point greater than a desired camber in the beam and holding the forward hydraulic lift cylinder at that point; second lifting at least one of the rear hydraulic lift cylinders to bend at least one cold steel beam of the providing step to a point greater than a desired camber in the beam and holding the rear hydraulic at that point; and lowering the forward and rear hydraulic lift cylinders and checking for desired final camber dimensions in the beam.
Related objects and advantages of the present invention will be apparent from the following descriptions.